In the past, it had been the convention, when crossmatching blood to determine compatibility of recipient and donor, that blood be taken with a pasteur pipet adapted with a bulb from a tube of blood attached to a donors blood bag and thereby to dispense said blood in a dropwise fashion. This tube of blood represented the donors blood and therefore was secured by tape to the donor bag and was identified as such by numbers coinciding with those appearing on the donor bag. It was found that some transfusion reactions were linked to incorrect indentification of this tube or the tube being placed on another bag accidentally. In view of this the American Association of Blood Banks and other concerned parties decided that a safer method of insuring correct blood sampling was to use the blood that was confined within the plastic tubing that was attached to the bag and had to definitely represent the donors blood. Blood is taken from a prospective blood donor using this plastic tubing about three feet in length, one end of which is permanently secured to the bag and the other end fitted with a needle. Using asceptic technique, vena puncture is made and blood is allowed to flow through the tubing by gravity into the bag until filled. At this point the tubing is clamped off near the needle and the tubing removed from the hub of the needle. Blood is then collected into a tube from the hub of the needle to be used for other donor testing such as syphilis, and hepatitis testing. The plastic tubing which had been previously clamped off so as to maintain a closed sterile system is then heat sealed along the length of the tubing at varying intervals two to four inches apart. This tubing commonly called the "sausage" is identified repetatively along its length by numbers coinciding with those on the bag. These numbers are put there by the manufacturer of the bag. During the compatibility testing, the technician cuts a segment of this tubing and squeezes it in order to dispense one or two drops of blood as needed. He then places the segment in a small tube which is attatched to the donor bag for future use.
This procedure has several drawbacks, namely, a scissors is needed to cut the tubing and repeatedly must be wiped clean since it is used to cut other segments representing different donors. Secondly, the tube containing the segment often falls to the ground and breaks due to improper securing to the bag. Thirdly, many technicians do not reuse the segment initially placed in the tube because they must check the number on said segment to insure proper identification. Often when the segment is cut the number has been partially cut as well. Consequently another segment is cut using the same procedure outlined, and often this segment is discarded rather than placing it in a tube etc.
The invention described herein eliminates the use of scissors, the need for a tube, and insures donor integrity. It can also cut down on the number of heat seals or segments heretofore needed along the length of the tubing.